Noise-enhanced contrast stretching of dark images in SVD-DWT domain
01 Dec 2013-pp 1-6
TL;DR: A noise-enhanced contrast stretching algorithm for enhancement of dark images in SVD-DWT domain has been presented and comparison with other SR-based and non-SR based algorithms shows noteworthy performance of the algorithm.
Abstract: A noise-enhanced contrast stretching algorithm for enhancement of dark images in SVD-DWT domain has been presented in this paper. A dark or low-contrast image is considered to be comprising a weak signal (information) and noise (due to insufficient illumination). Since singular values of an image represent luminance of independent image layers, the internal noise may be considered to be inherent in the singular values of the image, as well that of the wavelet approximation coefficients of a dark image. The singular values of the approximation coefficients are iteratively processed using the analogy of a double-well system exhibiting dynamic stochastic resonance (SR), where addition of noise is utilized to enhance system performance. Iteration is terminated with the criterion of target contrast and visual qualities. Comparison with other SR-based and non-SR based algorithms shows noteworthy performance of the algorithm in the SVD-DWT domain.
Citations
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TL;DR: The proposed noise-enhanced iterative processing on Fourier coefficients for enhancement of low-contrast images has been found to give noteworthy performance for both low- Contrast and dark images among the SR-based techniques and is found to be better than most of the non-SR- based techniques, in terms of contrast enhancement, perceptual quality and colorfulness.
Abstract: This paper presents a study of noise-enhanced iterative processing on Fourier coefficients for enhancement of low-contrast images. The processing equation is derived from the concept of dynamic stochastic resonance (SR), where the presence of optimum amount of noise produces an improved performance in the system. Similar to our earlier works on SR-based contrast enhancement, noise in the current context is the internal noise inherent in an image due to insufficient illumination. Here, however, the parameter selection is done so as to achieve large noise suppression. Iteration is terminated when target performance has been achieved. It is observed that the increase in the variance of the Fourier magnitude distribution leads to an increase in the contrast of the image. The increase in the variance is analytically proven to be equivalent to the process of coefficient rooting. Comparison has been made with various state-of-the-art SR and non-SR-based techniques in spatial/frequency domains. The proposed technique has been found to give noteworthy performance for both low-contrast and dark images among the SR-based techniques. The performance is also found to be better than most of the non-SR-based techniques, in terms of contrast enhancement, perceptual quality and colorfulness.
12 citations
TL;DR: An extensive literature review was conducted and the nighttime visual refinement approaches into nighttime restoration and enhancement were classified and identified the research gap fields to explore future research directions in nighttime visual enhancement techniques.
Abstract: Video surveillance systems substitute manual efforts in various safety critic domains such as border area, assisted living, banking, service stations, and transportation. The multimedia-based surveillance system has a significant role in security and forensic systems because people tend to be easily convinced after observing voice, image, and video. Hence, these videos are strong evidence in the forensic investigation. However, most of the criminal activities such as ATM robbery and assassination are occur at nighttime because of the crime supporting dark environment. Many of the night surveillance systems in military, as well as commercial applications, are equipped with infrared and thermal based night vision systems. Its poor capability of texture and color interpretations are the major issues to ensure secure nighttime video monitoring. Specifically, visual refinements of nighttime surroundings and foreground objects provide a valuable assistance in the nighttime security system. In this scenario, it is highly recommended a review of the state-of-the-art nighttime visual refinement approaches. We conducted an extensive literature review and classified the nighttime visual refinement approaches into nighttime restoration and enhancement. This comparative literary analysis identified the research gap fields to explore future research directions in nighttime visual enhancement techniques. Finally, we discussed various open issues and future directions in the context enhancement based nighttime enhancement research.
8 citations
TL;DR: It can be inferred from comparative analysis with respect to other conventional methods that while the algorithm is observed to work well in all three hybrid domains, the SV-DCT domain performs better in terms of iteration count, while DCT-DWT is found to outperform others in Terms of perceptual quality.
Abstract: This paper aims to present an analysis of a noise-aided contrast enhancement algorithm in hybrid transform domains. The performance of our earlier noise-enhanced iterative algorithm, formulated from the motion dynamics of a double-well system exhibiting dynamic stochastic resonance, has been investigated here on hybrid coefficients, viz. singular values (SVs) of wavelet coefficients, SVs of discrete cosine transform (DCT) coefficients, and DCT of wavelet coefficients, of a dark image. The performance of the algorithm is gauged using metrics indicating relative contrast enhancement and perceptual quality. Colorfulness, subjective visual scores and logarithmic contrast metrics for outputs are also observed. Experimental results display noteworthy enhancement of contrast on both natural and synthetically-darkened images. It can be inferred from comparative analysis with respect to other conventional methods that while the algorithm is observed to work well in all three hybrid domains, the SV-DCT domain performs better in terms of iteration count, while DCT-DWT is found to outperform others in terms of perceptual quality.
4 citations
References
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TL;DR: Experimental results show that Gaussian noise added to low-quality fingerprint images enables the extraction of useful features for biometric identification by adding noise to the original signal.
Abstract: This paper presents a new approach to enhancing feature extraction for low-quality fingerprint images by adding noise to the original signal. Feature extraction often fails for low-quality fingerprint images obtained from excessively dry or wet fingers. In nonlinear signal processing systems, a moderate amount of noise can help amplify a faint signal while excessive amounts of noise can degrade the signal. Stochastic resonance (SR) refers to a phenomenon where an appropriate amount of noise added to the original signal can increase the signal-to-noise ratio. Experimental results show that Gaussian noise added to low-quality fingerprint images enables the extraction of useful features for biometric identification. SR was applied to 20 fingerprint images in the FVC2004 DB2 database that were rejected by a state-of-the-art fingerprint verification algorithm due to failures in feature extraction. SR enabled feature extraction from 10 out of 11 low-quality images with poor contrast. The remaining nine images were damaged fingerprints from which no meaningful features can be obtained. Improved feature extraction using SR decreases an equal error rate of fingerprint verification from 6.55% to 5.03%. The receiver operating characteristic curve shows that the genuine acceptance rates are improved for all false acceptance rates.
69 citations
"Noise-enhanced contrast stretching ..." refers background in this paper
...The concept of ‘stochastic resonance’, where noise is utilized to amplify a weak subthreshold signal, has particularly been found to work remarkably in contrast enhancement of dark and low-contrast images [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]....
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TL;DR: The proposed DSR-SVD technique is found to give noteworthy better performance in terms of contrast enhancement factor, color enhancement factor and perceptual quality measure.
Abstract: In this paper, a dynamic stochastic resonance (DSR)-based technique in singular value domain for contrast enhancement of dark images has been presented. The internal noise due to the lack of illumination is utilized using a DSR iterative process to obtain enhancement in contrast, colorfulness as well as perceptual quality. DSR is a phenomenon that has been strategically induced and exploited and has been found to give remarkable response when applied on the singular values of a dark low-contrast image. When an image is represented as a summation of image layers comprising of eigen vectors and values, the singular values denote luminance information of each such image layer. By application of DSR on the singular values using the analogy of a bistable double-well potential model, each of the singular values is scaled to produce an image with enhanced contrast as well as visual quality. When compared with performance of some existing spatial domain enhancement techniques, the proposed DSR-SVD technique is found to give noteworthy better performance in terms of contrast enhancement factor, color enhancement factor and perceptual quality measure.
59 citations
"Noise-enhanced contrast stretching ..." refers background or methods in this paper
...The concept of ‘stochastic resonance’, where noise is utilized to amplify a weak subthreshold signal, has particularly been found to work remarkably in contrast enhancement of dark and low-contrast images [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]....
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...Readers are advised to refer to [9], [12] for a exhaustive mathematical formulation of the same in SVD and intensity domains respectively....
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...Eq 1, when discretized for this bistable double-well (as described in [9], [12]), produces the following iterative equation:...
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...Among SR-based techniques, comparison with singular-value-based DSR (SVDDSR) [9], DCT-DSR [10], DWT-DSR [11], and suprathreshold SR-based technique (SSR) [8] has been done....
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...For a visual comparison among various techniques, readers are advised to refer to [9], [11], [12]....
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TL;DR: A technique using stochastic resonance (SR)-based wavelet transform for the enhancement of unclear diagnostic ultrasound images that enhances the edges more clearly and can also optimally enhance an image even if the image noise level is considerable.
Abstract: Ultrasound diagnostic imaging technique is used to visualize muscles and internal organs, their size, structures and possible pathologies or lesions. The limited soft tissue contrast of ultrasound may lead to problems in characterizing perivascular soft tissues. We develop a technique using stochastic resonance (SR)-based wavelet transform for the enhancement of unclear diagnostic ultrasound images. The proposed method enhances the edges more clearly. The advantages of this method are that it can simultaneously operate both as an enhancement process as well as a noise-reduction operation, and that the method can also optimally enhance an image even if the image noise level is considerable.
58 citations
"Noise-enhanced contrast stretching ..." refers background in this paper
...The concept of ‘stochastic resonance’, where noise is utilized to amplify a weak subthreshold signal, has particularly been found to work remarkably in contrast enhancement of dark and low-contrast images [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]....
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24 Nov 2003
TL;DR: A SR-based Radon transform is presented, in which a bistable stochastic resonance structure is introduced into theRadon transform, which can easily extract weak lines from noise images and give applications in the bearing-time record and the LOFAR display.
Abstract: The Radon transform is able to transform two dimensional images with lines into a space of line parameters, where each line in the image will give a peak positioned at the corresponding line parameters. This has led to many line detection applications in image processing, computer vision and array processing. But when the lines are embedded in very strong noise background, using the Radon transform directly is not so effective. In this paper we present a SR-based Radon transform, in which a bistable stochastic resonance structure is introduced into the Radon transform. Using this kind of transform, we can easily extract weak lines from noise images. We also give applications in the bearing-time record and the LOFAR display.
46 citations
"Noise-enhanced contrast stretching ..." refers background in this paper
...The concept of ‘stochastic resonance’, where noise is utilized to amplify a weak subthreshold signal, has particularly been found to work remarkably in contrast enhancement of dark and low-contrast images [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]....
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24 Oct 2004
TL;DR: The results show that the proposed method is suitable for noisy images with very low signal-to-noise ratio (SNR), when the texture of the object is not subtle, and the region where the object lies in is not too small compared to the minimal region coverage over which SR works.
Abstract: This paper presents an image enhancement method using stochastic resonance (SR) and provides two applications to sonar image processing., i.e. side-scan sonar image and bearing-time record. Simulated and real data are tested and the results show that the proposed method is suitable for noisy images with very low signal-to-noise ratio (SNR), when the texture of the object is not subtle, and the region where the object lies in is not too small compared to the minimal region coverage over which SR works. We also show that an additional amount of noise besides the noise of the image itself may be helpful in enhancing the image.
43 citations
"Noise-enhanced contrast stretching ..." refers background in this paper
...The concept of ‘stochastic resonance’, where noise is utilized to amplify a weak subthreshold signal, has particularly been found to work remarkably in contrast enhancement of dark and low-contrast images [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]....
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